Odometer



Oct'. 6, 1931. C, B .NSMORE 1,826,391

ODOMETER Filed Dec. 7, 1928 Patented Oct. 6, 1931 UNITED-STATES PATENT oFl-icE enenn-nonk B.

PANY, OF FLINT,`MICHIGAN, AjCOMPANY OF MICHIGAN oDoMETER Application led December This invention relates to measuring instruments and has been designed as an improve- .ment in the odometer element of a combined speedometer andk odometer as used on motor vehicles.

An object of the invention is to render more free and smooth the rotation of the iigure wheels of the odometer.v

Another object is to lessenthe friction be- 1 tween adjacent figure wheels of an odometer 1:: driven the one from the other by star pinions located within the periphery of the wheels, the power transmission being through the instrumentality of internal gears and transverse lugs on the several wheels.

Fig. l illustrates a speedometer of the type described, in side elevation with parts broken away and in section. Fig. 2 is a front elevation also partly broken away and in section.

In structures of this kind a fixed shaft has been used for the rotatable support of a series of figure wheels. The wheels have been provided on the under side of their rims with interior teeth at one edge and with transfer o lugs on the other edge. Between the figure wheels there have been used transfer pinions carried by transfer pinion carriers. These carriers have been provided with apertures to receive the figure wheel shaft and with means e5 whereby they are held from rotation. vSuch carriers have been of substantially the same radial dimension as the figure wheels and they have spaced the wheels apart to the extent of their own thickness. To maintain thestar te pinion or transfer pinion in accurate drivingv 7, 192s. Serin No. 324,405.-

relation with the transfer lug and the internal gear such pinions have been provided With circumferential grooves engaging in a slot of the pinion carrier.

mechanism.

With suchV a construction it will be understood that there is an annular ring on each DINSMORE, OF FLINT, MICHIGAN, ASSIGNOR T0 A C SPARK PLUG COM- "l No novelty is herein j x claimed for the above described transfer-` side of each figure wheel and that these rings j bear against the spacing pinion carrier with the result that some friction is developed between the face of the wheel andthe carrier whenever the wheel turns. This friction, al-

though slight, is notr negligible. When more ,l

than a single-.wheel is being turned it is obviously multiplied and will act substantially like a multiple disc clutch and tend to retard the action of the figure wheels, requiring a greater effort in proportion to the number of wheels to be turned at any one time. There results in consequence a variable resistance caused by this friction and a jerky action of the driving mechanism takes place owing to this variability of the load to be overcome.

The condition is more pronounced in the'case of a Worm drive for the odometer wheels since such a drive develops an end thrust whereby f the friction between the figure wheels and the pinion carrier is augmented. This difficulty is of course less with other types of drives and may be reduced to a minimum through the adoption ofthe ratchet type of drive as illustrated in the drawings. f

The present invention not only aims to veliminate as faras possible this disadvan- 'tageous friction but even more to utilize the reduced friction which is negligible as far as its influencein retardingzthe yrotation of one wheel relative to another is concerned, to aid each Wheel in turningthe next as it does through the instrumentality. of the star pin- 'lOIL l A f In the drawings numeral 1 represents a casing to inclose a frame 2 carrying both the speedometer andthe odometer. The speedometer includes a rotating bar magnet 3, a conical field plate 4, and a rotatable conical speed cup 5, this speed cup being,fas shown, between the vmagnet and the lield plate. The ,A details of the speedometer form no partof las the measuring instrument and need be no further described.

The odometer includes a driven decimal wheel 9 provided on its hub with an annular flange carrying fixed thereto a ratchet wheel 11. This ratchet wheel is to be driven by a paWl 7 actuated by an eccentric not shown on the end of the so-called second worm shaft. Retarding brake means for steadying the action of figure wheell9 Vis shown atB. The wheel 9 with the ratchet 11 and the coaxial figure wheels are mounted on shaft 13 which is supported in arms 1Q constituting a part of the die cast frame 2. n

T he several wheels are provided with hubs which are in contactbut are of such axial dimensions as to space the peripheral portions of the wheels 'from each other. As shown the wheel 9has a hub 1% inkcontact with hub 1G ofthe adjacent wheel. The hub 14 is shouldered and on the shoulder is freely mounted a star pinion carrier or disc 15. The shoulder of hub 14C is so positioned as to position the carrier or. disc -15 axially between the peripheries of the two adjacent figure wheels. The hubs are alsoof such dimension as to space the peripheries of these wheels from the intermediate disc 15. The disc is furthermore so positioned that the star pinion carried thereby will be in correct operating relation with the transfer lugs of one wheel and the driven teeth of the other. rlhe carrier or disc 15 in addition to being freely mounted on the hub of wheel9 is held in position and from rotation by a projection 17 entering a frame slot provided for this purpose.

By the arrangement described the annular parts of the wheels at their circumferences do not frictionally engage the pinion carrier, the friction being greatly lessened andtaking place only between the adjacent hubs 14 and 16.

Any existing friction between these hubs, although negligible insofar as it retards the rotation of one wheel relative to the other, does tend to'rotate the second wheel inthe direction of the rotation of the first Wheel. This is of use when the first Wheel is actually rotating the second through the instrumentality of the star pinion. A smooth and comparatively effortless action is produced for the rotation of thevodometer wheels as a Whole, the action through friction between the wheel hubs tending to rotate each successive adjacent figure wheel in. unison with the rotation being imparted to it through the star pinion from the adjacent wheel .of lower denomination. A construction such as described will produce in addition to its better action a greater etliciency and a more durable instrument and one having longer life.

` l claim:

1. In a measuring instrument, a plurality of coaxial figure wheels, said figure wheels having their hubs in contact, internal transfer mechanism for said wheels including a pinion carrier freely mounted on one of said hubs, said carrier being substantially of the same radial dimension as Said Wheels, means t0 hold said carrier from rotation, said hubs being dimensioned to space the wheel peripheries 'from said` carrier.

In a measuring instrument, a pluralityofcoaxial figure wheels, said figure Wheels haingtheir hubs incontact, said hubs being axially dimensioned to space the Wheel peripheries from contact with each other, said contacting hubs including a. radially reduced portion adjacent the contacting surface, said reduced portion being Within the plane of the space between the wheel peripheries, a pinion carrier mounted on said reduced hub portion, means to prevent rotation of said pinion carrier, and a transfer pinion carried by said carrier in operative relation to said ligure wheels.

ln testimony whereof I aix my siunature.

CLARENCE B. DiNsMRE. 

